The Use of Botulinum Toxin in Strabismus Treatment

Diclofenac Versus Corticosteroids Following Strabismus Surgery: Systematic Review and Meta-analysis

The purpose of the current study was to compare outcomes of diclofenac versus corticosteroids following strabismus surgery. A systematic review and meta-analysis were performed in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. An electronic search was performed to include comparative studies of diclofenac versus corticosteroids following strabismus surgery. The analysis was based on fixed and random effect models. Primary outcomes included discomfort, chemosis, inflammation, conjunctival gap, intraocular pressure, and conjunctival injection. Secondary outcomes were conjunctival congestion, discharge, and drop intolerance. Eight studies with a sample of 469 eyes were included. At weeks 1 and 4 postoperatively, there were no statistically significant differences between the diclofenac and corticosteroid groups, except for conjunctival injection at week 1 (mean difference [MD] = -0.21, P = .04) favoring diclofenac. Interestingly, all primary outcomes significantly favored diclofenac at week 2: discomfort (MD = -0.34, P = .03), conjunctival chemosis (MD = -0.16, P = .04), conjunctival inflammation (MD = -0.16, P = .02), conjunctival gap (MD = -0.17, P = .002), intraocular pressure (MD = -2.53, P < .00001), and conjunctival injection (MD = -0.30, P = .03). Moreover, conjunctival congestion was significantly improved for dexamethasone, whereas discharge and drop intolerance was not statistically different. Diclofenac is comparable to various corticosteroids when used following strabismus surgery. However, it is important to note that diclofenac yielded significant improvements in discomfort, conjunctival chemosis, inflammation, conjunctival gap, intraocular pressure, and conjunctival injection, mainly at 2 weeks postoperatively. [J Pediatr Ophthalmol Strabismus. 2023;60(5):312-322.].

Botilinum toxin in the treatment of strabismus

Introduction: Strabismus is an oculomotor imbalance that occurs in 0.5 to 5% of the population. There are various etiopathogenetic theories and several modalities of treatment. One of these modalities is the application of botulinum toxin intramuscularly. This chemodenervation causes temporary muscle paresis which acts as a recession while its antagonist contracts. This achieves a temporary correction of strabismus. However, further research is needed. The aim of the paper was evaluation of published research studies on botulinum toxin as a treatment option in strabismus, as a primary and adjuvant therapy and as a preventive therapy in patients with abducens nerve palsy. For this purpose, we searched the major databases of the medical publications Medline and Pubmed, using keywords: strabismus, botulinum toxin. We found more than 50 articles related to our search for the last 30 years, 30 of which have been used for this review. In this review paper we have presented the most important insights from the literature, as well as our opinions and insights on the topic. Although further studies are needed regarding dosing as well as avoiding side effects, botulinum toxin has been shown to be a good alternative and adjunctive therapy to strabismus surgery, with the downside being that the effect is temporary. Positive effects and faster recovery have also been shown in patients with abducens nerve palsy.

Management of Thyroid Eye Disease: A Consensus Statement by the American Thyroid Association and the European Thyroid Association

Thyroid eye disease (TED) remains challenging for clinicians to evaluate and manage. Novel therapies have recently emerged, and their specific roles are still being determined. Most patients with TED develop eye manifestations while being treated for hyperthyroidism and under the care of endocrinologists. Endocrinologists, therefore, have a key role in diagnosis, initial management, and selection of patients who require referral to specialist care. Given that the need for guidance to endocrinologists charged with meeting the needs of patients with TED transcends national borders, and to maximize an international exchange of knowledge and practices, the American Thyroid Association and European Thyroid Association joined forces to produce this consensus statement.

Management of thyroid eye disease: a Consensus Statement by the American Thyroid Association and the European Thyroid Association

Thyroid eye disease (TED) remains challenging for clinicians to evaluate and manage. Novel therapies have recently emerged, and their specific roles are still being determined. Most patients with TED develop eye manifestations while being treated for hyperthyroidism and under the care of endocrinologists. Endocrinologists, therefore, have a key role in diagnosis, initial management, and selection of patients who require referral to specialist care. Given that the need for guidance to endocrinologists charged with meeting the needs of patients with TED transcends national borders, and to maximize an international exchange of knowledge and practices, the American Thyroid Association and European Thyroid Association joined forces to produce this Consensus Statement.

Binocular Visual Rehabilitation in Paralytic Strabismus by Botulinum A Toxin Chemodenervation

Purpose

To investigate the effect of botulinum A toxin (BTXA) chemodenervation in paralytic strabismus patients without surgical correction.

Methods

A retrospective chart review of 51 patients who were diagnosed as paralytic strabismus and underwent BTXA chemodenervation was performed. The patients were divided into four groups according to the cause of paralytic strabismus of vasculopathy, neoplasm, trauma, and idiopathic. They were also divided into two groups of early and late treatment according to the initiation time of BTXA chemodenervation after the onset of strabismus (3 months), and of the initial strabismus type of exotropia and esotropia. We investigated the changes of angle of deviation and diplopia after BTXA chemodenervation.

Results

The average deviation of angles decreased by 25.2 prism diopter (PD) (35.1 to 9.9 PD) in total patients, and the overall success rate was 64.7% (33 by 51), and the there was no statistically significant difference in success rate between each group divided by the cause of paralytic strabismus. According to the treatment timing, the deviation of the angle decreased by 28.0 PD (36.8 to 8.8 PD) in the early treatment group, and 21.3 PD (33.5 to 12.2 PD) in late treatment group at the time of the last postinjective follow-up. According to the initial strabismus type, the average angle of deviation decreased by 20.3 PD (35.6 to 15.3 PD) in exotropia group by cranial nerve 3 palsy, and 24.4 PD (32.5 to 8.1 PD) in esotropia by cranial nerve 6 palsy.

Conclusions

BTXA chemodenervation reduced the angle of deviation and the number of patients with diplopia regardless of the cause of paralytic strabismus. Early BTXA chemodenervation can be considered as the first treatment of choice in paralytic strabismus, especially in esotropia patients.

Hemifield-slide diplopia successfully managed with botulinum toxin injection in a patient with traumatic chiasmal disruption

PURPOSE

This report describes the clinical course of the traumatic chiasmal syndrome and treatment of diplopia due to the hemifield-slide phenomenon.

CASE REPORT

A 20-year-old male with decreased vision in both eyes following blunt head trauma was referred to the neuro-ophthalmology clinic. Neuroimaging revealed disruption of the optic chiasm and skull base fracture. After partial vision recovery, the patient noticed complete bitemporal hemianopia. Three months later, he was exotropic and complained of diplopia and difficulty in near visual tasks. His symptoms were successfully controlled by injection of botulinum toxin A in both lateral rectus muscles.

CONCLUSIONS

There is some potential for improvement in vision in patients with traumatic chiasmal syndrome. Botulinum toxin could be used in patients with the hemifield-slide phenomenon to predict the sensory outcome of surgery and relieve the bothersome symptoms.

Efficacy of botulinum toxin injection in exotropia treatment

PURPOSE:

Botulinum toxin (Botox) therapy is a well-known option for strabismus management and is often used in managing esotropia. Exotropia is also a common type of strabismus; however, the effectiveness of Botox in improving exotropia is still ambiguous. In this study, we report our experience in using Botox to manage the various types of exotropia.

METHODS:

A retrospective cohort study was conducted at King Khaled Eye Specialist Hospital Riyadh, Saudi Arabia. Medical records of patients with exotropia who received Botox from 2014 to March 2020 were reviewed. The main success indicator was a remaining angle of less than 10 prism diopters (PD).

RESULTS:

A total of 97 cases were reviewed, with 57 (58.8%) males and 40 (41.2%) females. The age ranged from 2 months to 40 years. The most prevalent diagnosis was sensory exotropia. Overall, 28 patients (28.9 %) and 49 patients (50.5%) achieved an angle of deviation within 10 PD and within 20 PD, respectively. Female patients had a better response to Botox than males, with 32.5% of them achieving an angle of deviation within 10 PD and 60% achieving an angle of deviation within 20 PD. We found that the change in the angle of deviation increased as the Botox dose was increased.

CONCLUSION:

Botox represents a possible safe alternative to surgery in the management of some exotropia types. The success rate differs by type, with basic exotropia scoring the highest. The presence of poor vision and amblyopia leads to a significantly lower success rate.

Comparison of the therapeutic effects of surgery following prism adaptation test versus surgery alone in acute acquired comitant esotropia

BACKGROUND

To compare the therapeutic effects of surgery following prism adaptation test versus surgery alone in acute acquired comitant esotropia (AACE).

METHODS

A total of 46 patients with AACE were enrolled in this retrospective study. Among them, 26 patients underwent surgery following prism adaptation test (combination group) and 20 patients underwent surgery alone (surgery group). The following parameters were evaluated including success rate, distant and near deviation angles, visual function, and near stereoacuity.

RESULTS

There were no significant differences in success rate between the combination group and surgery group at post-treatment 12 months (96.15% vs. 90.00%, p > 0.05). The postoperative distant and near deviation angles in two groups were significantly lower than that before surgery (p < 0.05). In addition, the numbers of patients with stereopsis postoperatively in two groups were significantly higher than that before surgery (all p < 0.05). Moreover, the numbers of patients with stereopsis and central stereopsis in the combination group were significantly higher than that in the surgery group postoperatively. At post-treatment 12 months, one (3.85%) case recurred in combination group and three (15.00%) cases in the surgery group. No complications were observed in the two groups.

CONCLUSIONS

Both approaches had therapeutic benefit in AACE. Surgery following prism adaptation test had better treatment benefits than surgery alone in improving binocular function and reducing recurrence rate.

Minimal invasive vertical muscle transposition for the treatment of large angle exotropia due to congenital medial rectus hypoplasia: Case Report and Literature Review

Reports of isolated anomalies of the medial rectus (MR) muscle in literature are sparse. It has been identified as a subtype of congenital cranial dysinnervation disorder that affects the normal development of brainstem motor neurons. Herein, we report a 37-year-old male presented with large-angle exotropia since the birth of right eye with palpebral fissure widening. On examination of ocular movements, there was -6 limitation of adduction. There was no limitation in other ocular movements. In the preoperative CT scan, all extraocular muscles were present. He underwent surgery in right eye. Intraoperatively in the site of medial rectus, we found an empty sheath without muscle fibers indicating medial rectus hypoplasia. The width of muscle insertion was normal. Surgery consisted of lateral rectus muscle recession 10 mm in hang-back method and vertical muscle transposition procedure, by a modification of Nishida technique, in which the vector of superior and inferior recti was transposed medially by inserting non-absorbable sutures at nasal margins of muscles secured to sclera 8 mm posterior to medial rectus site without tenotomy or splitting. The deviation was decreased to less than 10 PD exotropia in primary position. The adduction was improved from -6 to -4. The palpebral fissure asymmetry was also corrected. Here, we also reviewed clinical features of all cases of medial rectus hypoplasia/aplasia in the literature and discussed surgical approaches. For vertical rectus transposition and horizontal muscle weakening, this technique has the advantages of being simpler and less traumatic to ocular tissues and unlike the traditional transposition procedures, there is no need for tenotomy and splitting.

Differences of a Single Injection of Botulinum Toxin A between Infantile and Nonaccommodative Esotropia

PURPOSES

To compare the results of a single injection of botulinum toxin A (BTA) between children with infantile esotropia (IET) and nonaccommodative esotropia (NAET) during the first 2 years.

METHODS

Retrospective study that included 23 children with IET and 25 with NAET. At 6 months, 1 and 2 years after treatment, the deviation and stereoacuity were evaluated.

RESULTS

At 6 months and 1 year after treatment there was no difference in ocular alignment between the two groups (success criteria were achieved in 36.8% in IET group and 60.0% in NAET at 6 months p = .129, and 57.9% in IET group and 68.0% in NAET group at 1 year p = .352). Two years after treatment, there were statistical differences between motor alignment (IET group 21,1% and NAET group 60.0%, p = .007) and stereoacuity (IET group 40% and NAET group 90%, p = .004) between the two groups. Although side-effects affected most children during the first week (in the first week, overcorrection was present in 16 (84.2%) children with IET, and in 19 (76.0%) children with NAET; and ptosis affected 15 (78.9%) children with IET and 17 (68.0%) children with NAET), at 6 months all the effects have disappeared on both groups.

CONCLUSIONS

We recommend BTA as an alternative, but not as definite treatment in IET if the surgeon/parents are not comfortable with an early strabismus surgery; but retreatment or surgery will have to be considered after 1 year. On the contrary, BTA may be a first-line treatment of NAET because it is an easy, safe and has a long-lasting effect.